Surah Al-Isra 17:12

وَجَعَلْنَا ٱلَّيْلَ وَٱلنَّهَارَ ءَايَتَيْنِ ۖ فَمَحَوْنَآ ءَايَةَ ٱلَّيْلِ وَجَعَلْنَآ ءَايَةَ ٱلنَّهَارِ مُبْصِرَةً لِّتَبْتَغُوا۟ فَضْلًا مِّن رَّبِّكُمْ وَلِتَعْلَمُوا۟ عَدَدَ ٱلسِّنِينَ وَٱلْحِسَابَ ۚ وَكُلَّ شَىْءٍ فَصَّلْنَـٰهُ تَفْصِيلًا

And We have made the night and day two signs, and We erased the sign of the night and made the sign of the day visible that you may seek bounty from your Lord and may know the number of years and the account [of time]. And everything We have set out in detail.

Translation: Saheeh International

Tafsir

And We made the night and the day two signs both indicators of Our power. Then We effaced the sign of the night extinguishing its light with darkness so that you might repose therein the annexation āyata’layli ‘the sign of the night’ is explicative and made the sign of the day sight-giving in other words one in which …

Excerpt from Tafsir al-Jalalayn, commentary on 17:12, via Quran.com. The reader has the full commentary and 9 more tafsirs.